Senator Bernie Sanders, who has made a $15 minimum wage a centerpiece of his campaign’s pledge to fight income inequality, won the nation’s first Democratic presidential primary Tuesday in New Hampshire, and did so by a substantial margin. With nearly all the votes tallied, Mr. Sanders garnered 60.4 percent of the vote, compared to 38 percent for former Secretary of State Hillary Clinton, a 22 point margin.

Both Sanders and Clinton strongly favor raising the federal minimum wage, which remains stuck at the poverty-level $7.25 per hour due to Congressional Republicans’ refusal to consider raising it. Mrs. Clinton supports the Senate Democratic leadership’s proposal for a phased-in $12 federal minimum wage by 2020, and has endorsed higher local minimum wages, including cities moving to a $15 wage floor. But she raises the issue less frequently than Sanders does, and has noted her opposition to Sanders’s call for a $15 federal minimum wage. In contrast, Sanders makes his support of a $15 minimum wage an almost constant component of his campaign message. None of the remaining Republican presidential candidates supports raising the federal minimum wage.

Exit polling from New Hampshire’s Democratic presidential primary shows that Sanders’s emphasis on fighting income inequality, supporting higher wages and benefits for workers, and a $15 minimum wage helped earn him his strongest support from lower-income working people. Among voters in the Democratic primary with incomes of less than $30,000 per year (equivalent to $14.42 per hour for 40 hours a week year-round), Sanders received 72 percent of their votes compared to 24 percent for Clinton. That margin of roughly 16,500 votes represented nearly a third (29.5 percent) of Sanders’s total vote margin. Among Democratic primary voters from households with combined incomes of less than $50,000 per year, Sanders received 65 percent of the vote compared to 32 percent for Clinton, with his vote margin among those voters being almost half (44.9 percent) of his total margin. The only income group in which Clinton outpolled Sanders Tuesday was among voters with incomes of $200,000 per year or more.

Also notable in the exit polling, the two most important issues identified by Democratic primary voters were the economy and jobs (33 percent) and income inequality (32 percent). Voters who said income inequality was the most important issue favored Sanders by a 71 to 29 margin, while those who said the economy and jobs were most important voted for Sanders 59 to 39. And those who reported voting in a Democratic primary for the first time favored Sanders by 78 percent to 21 percent for Clinton.

Entrance and exit polls from the Iowa Democratic caucuses also showed Sanders’s support strongest among lower-income voters. There, he won among voters from households with incomes of less than $30,000 and $50,000 per year, but by smaller margins than in New Hampshire. Iowa Democratic caucus voters from households earning less than $30,000 favored Sanders by a 57 to 41 margin; those from households with incomes of less than $50,000 supported Sanders 53 to 44. But, in contrast to New Hampshire, Clinton won among voters in all income groups from households of $50,000 or more, and did so by a ten-point margin, 52 to 42.

In New Hampshire, Sanders began his campaign with little support despite hailing from the neighboring state of Vermont. The day after he announced his candidacy for the Democratic nomination last April, polls showed him at just 11.3 percent in New Hampshire—40 points behind Clinton. By the time he joined workers at a Fight for $15 rally outside the U.S. Capitol last July—the same day he introduced his federal $15 minimum wage bill in Congress—he had narrowed the gap in the polls to trail Clinton by less than 17 points. Sanders then elevated his call for a $15 minimum wage to the top of his campaign’s agenda, and within two months, the poll numbers in New Hampshire had swung by 30 points to show him leading by nearly 13 points. And while his poll numbers continued to solidify through the fall, his 22 point margin in Tuesday’s primary was more than 8 points higher than even his average lead in the most recent polls.